feat(coding-agent/core): standardized timeout units and parameter naming across tools

- Standardized timeout parameters across all tools to use seconds instead of milliseconds.
- Added automatic conversion and validation for timeout values with reasonable clamping ranges.
- Renamed web-search parameter from num_results to limit for consistency.
- Updated parameter naming from camelCase to snake_case format across tools.

packages/coding-agent/test/tools/python-execution.test.ts

@@ -40,7 +40,7 @@ describe("python tool execution", () => {
 		const tool = new PythonTool(createSession(tempDir.path));
 		const result = await tool.execute(
 			"call-id",
-			{ cells: [{ code: "print('hi')" }], timeout_ms: 5000, cwd: tempDir.path, reset: true },
+			{ cells: [{ code: "print('hi')" }], timeout: 5, cwd: tempDir.path, reset: true },
 			undefined,
 			undefined,
 			undefined,